1. Field of the Invention
The present invention relates to oral surgery methods, and particularly to a tunneling method for dental block grafting that increases the thickness of the soft tissue of the mouth prior to performing block grafting procedures for dental implants.
2. Description of the Related Art
A dental implant is an artificial tooth root replacement and is used in prosthetic dentistry to support restorations that resemble a tooth or group of teeth. Prior to commencement of surgery, careful and detailed planning is required to indentify vital structures such as the inferior alveolar nerve or the sinus and to properly orientate the implants for the most predictable outcome. Two-dimensional radiographs, such as periapicals or orthopantomographs, are taken prior to the surgery.
In its most basic form, the placement of an osseointegrated implant requires a preparation into the bone using either hand osteotomes or precision drills with highly regulated speed to prevent burning or pressure necrosis of the bone. After a variable amount of time to allow the bone to grow onto the surface of the implant (osseointegration), a tooth or teeth can be placed on the implant. The amount of time required to place an implant will vary depending on the experience of the practitioner and difficulty of the individual situation.
At edentulous (without teeth) jaw sites, a pilot hole is bored into the recipient bone, taking care to avoid the vital structures (in particular the inferior alveolar nerve (IAN) and the mental foramen within the mandible). Drilling into jawbone usually occurs in several separate steps. The pilot hole is expanded by using progressively wider drills (typically between three and seven successive drilling steps, depending on implant width and length). Care is taken not to damage the osteoblast or bone cells by overheating. The implant screw can be self-tapping, and is screwed into place at a precise torque so as not to overload the surrounding bone (overloaded bone can die, a condition called osteonecrosis, which may lead to failure of the implant to fully integrate or bond with the jawbone). Typically, in most implant systems, the osteotomy or drilled hole is about 1 mm deeper than the implant being placed, due to the shape of the drill tip. Surgeons must take the added length into consideration when drilling in the vicinity of vital structures.
Traditionally, an incision is made over the crest of the site where the implant is to be placed. This is referred to as a “flap”. Some systems allow for “flapless” surgery, where a piece of mucosa is punched-out from over the implant site. Proponents of “flapless” surgery believe that it decreases recovery time, while its detractors believe it increases complication rates because the edge of bone cannot be visualized. Because of these visualization problems, flapless surgery is often carried out using a surgical guide constructed following computerized 3D-planning of a pre-operative CT scan. The amount of time required for an implant to become osseointegrated is a widely debated topic. Consequently, the amount of time that practitioners allow the implant to heal before placing a restoration on it varies widely. In general, practitioners allow 2 to 6 months for healing, but preliminary studies show that early loading of implant may not increase early or long term complications.
When an implant is placed, either a healing abutment, which comes through the mucosa, is placed, or a “cover screw” is used, which is flush with the surface of the dental implant. When a cover screw is placed, the mucosa covers the implant while it integrates, then a second surgery is completed to place the healing abutment. Two-stage surgery is sometimes chosen when a concurrent bone graft is placed or surgery on the mucosa may be required for esthetic reasons. Some implants are one piece so that no healing abutment is required.
For a dental implant procedure to work, there must be enough bone in the jaw, and the bone has to be strong enough to hold and support the implant. If there is not enough bone, more may need to be added with a bone graft procedure. In cases with severe ridge deficiency, block grafting is the recommended procedure to build the ridge prior to dental implant placement. One of the most important factors in the success of block grafts is adequate and maintained soft tissue coverage. Mucosal dehiscence and premature exposure of the autogenous block graft are the most common cause of graft failure.
Thus, a tunneling method for dental block grafting solving the aforementioned problems is desired.